Abstract
Barbara Mertens1, Tatiane Cristina de Araujo Nogueira1, Dimitrios Topalis1, Ruzena Stranska1, Robert Snoeck1,* and Graciela Andrei1,*
1Rega Institute for Medical Research, KU Leuven, Leuven, Belgium
*Graciela Andrei and Robert Snoeck share senior authorship
Correspondence to:
Barbara Mertens, email: barbara.mertens@kuleuven.be
Keywords: tumor-tumor interactions; SiHa cervical carcinoma; double xenograft model; cidofovir; far-reaching antitumor effects
Received: December 09, 2017 Accepted: March 27, 2018 Published: April 24, 2018
ABSTRACT
Tumor-tumor distant interactions within one organism are of major clinical relevance determining clinical outcome. To investigate this poorly understood phenomenon, a double human cervical xenograft model in nude mice was developed. A first tumor was induced subcutaneously by injection of human papillomavirus positive cervical carcinoma cells into the mouse lower right flank and 3 weeks later, animals were challenged with the same tumor cell line injected subcutaneously into the upper left flank. These tumors had no direct physical contact and we found no systemic changes induced by the primary tumor affecting the growth of a secondary tumor. However, ablation of the primary tumor by local treatment with cidofovir, a nucleotide analogue with known antiviral and antiproliferative properties, resulted not only in a local antitumor effect but also in a temporary far-reaching effect leading to retarded growth of the challenged tumor. Cidofovir far-reaching effects were linked to a reduced tumor-driven inflammation, to increased anti-tumor immune responses, and could not be enhanced by co-administration with immune stimulating adjuvants. Our findings point to the potential use of cidofovir in novel therapeutic strategies aiming to kill tumor cells as well as to influence the immune system to fight cancer.